BOM forecaster Jenny Sturrock says the cyclone has been upgraded to a category two system and is expected to become a category three or "severe" storm within 24 hours.

"During Monday, gales and heavy rainfalls are expected to extend to the Mardi and possibly as far west as Exmouth," she said.

"Then to the inland Pilbara late on Monday and Tuesday as Cyclone Christine intensifies up to category three and that's basically going to mean very destructive winds with gusts in excess of 170km per hour near the cyclone centre."

The weather bureau is warning residents on the coast between Pardoo and Mardi along the Pilbara coast of potentially dangerous storm tides in the region on late today or early tomorrow, with damaging waves and coastal inundation a possibility.

Ms Sturrock says the destructive winds could cause extreme damage.

"Especially if people haven't got in early and tied things down, making sure that we can't have anything that's going to cause extra debris. Basically getting everyone ready at the moment as they brace for the impact," said Ms Sturrock.

A yellow alert has now been issued for an area including Karratha, Wickham and Marble Bar.

Neil Bennett, from BOM, says the cyclone could bring destructive winds and a very dangerous storm tide.

"This is a dangerous system, as we keep stressing, so not to be taken lightly at all," he said.

"The combination of very strong winds and a storm surge overnight tonight does mean this probably one of the worst case scenarios we can look at, so this is potentially a very dangerous system."

Emergency services have issued community alerts and local governments say cyclone preparations are in place.

"The community has been very busy and it's great to see people have done their preparations in terms of taking down shade sails, making sure bins and other items are secured safely.

"In terms of the Town of Port Hedland, we've made sure all our parks and public reserves are ready with our shade sails and bins, getting sandbags ready to be delivered to public buildings and also working on retic (irrigation) systems, getting ready to turn off barbecues and so on."

Lynne Cragie from the Pilbara Regional Council says having large numbers of residents and workers away for the Christmas period has been an obstacle, but authorities are confident the town is prepared.

"We do hope that before people go on holidays at this time of year they get their yards prepared and make the place cyclone-proof," Ms Cragie said.

"But of course you can't guarantee that so the other thing is to ask people to keep an eye out for the yards of their neighbours to make sure precautions have been taken."

Both Qantas and Virgin say they are closely monitoring the situation but there is no planned alterations to flight schedules at this stage.

The WA cyclone season begins in November and continues through to April.

The Pilbara coast experiences more cyclones than any other part of Australia, according to the weather bureau.